valve question

Have a question about valve locks. Usually I just buy assembled heads, so I feel a little clueless. I dissasembled a set of 350 heads and had them cleaned, checked, and ground. I'm putting in a new set of valves, springs, locks, retainers etc...
On my old valves, right under the locks was a second groove with a plastic ring in it. The new valves have the same grooves but no plastic ring. What was that ring? Most of them were broken on the old valves as were the umbrella seals.

The plastic "ring" was in actuality, what G.M. called a valve oil seal. they harden with use, and break apart. Are You putting on P.C. seal's? If so, have the machine shop, cut the guide's, for P.C. seal's, They'll know what Your'e talking about. /forums/images/graemlins/grin.gif

In the old day's P.C. referred to Perfect Circle, [brand name] of seal's, Today, all machine shop's will recognize what P.C. is, and what You are talking about. The guide's will have to be cut with "Fly cutter attachment" to machine down the outside of the guide's, to accept p.c. seal's.

No You don't need the "ring" on the valve's, just throw them away.

P.C. seal's are on the valve stem at all time's, actually sealing oil out. The o.e.m. "ring" seal's were a haphazard affair that usually worked till the vehicle was out of warranty, then the hardened, fell apart, and the rig started using oil. /forums/images/graemlins/grin.gif

Up here, they charge around $15.00 to do all 16 Guide's. It's a very cheap upgrade, but the seal's work great. Also check into having them put in bronze insert's into the guide's, bronze wear's alot better than cast iron, and Knurling guide's is a waste of money. /forums/images/graemlins/grin.gif

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